1. For gluten, combine the water, kombu, soy sauce, and ginger in a large pot. Bring it to a boil while you do the next steps. Combine the rest of the gluten ingredients inside a large bowl. Mix until well combined. Knead for a bit. Let the dough rest for 5 minutes. Knead again, then let rest for another15 minutes. Spread dough on a cutting board, form into a log, and cut into 5-6 pieces.
2. Take out kombu from the pot. Place pieces in pot and let simmer for 1 hour. Rotate them occasionally so they do not stick to the bottom of the pot. When done cooking, rip apart the gluten into tiny pieces. For sauce, combine all sauce ingredients. Combine gluten with sauce. Let marinate for 24-72 hours.
3. For stirfry, combine all stir fry ingredients in a large wok. Place marinated seitan in the wok. Cook for 15-20 minutes until the onions are translucent. For bun dough, combine all bun ingredients. Let rise for 30-45 minutes in an oiled bowl. Cover bowl with foil while rising.On a floured cutting board, cut strip pieces of the dough.
4. To build char siu bao, get your steamer ready while you are doing the next steps. Use banana leaves or wax paper to line the bamboo steamer before you place bao's inside. On floured cutting board, take one strip of dough, form into a ball, and then flatten with hands or rolling pin. Take several teaspoons of the char siu stir-fry and put in the middle of your dough circle.
5. Form into a bao by taking the sides, bring them up to the top middle of the dough circle (making sure your mixture does not fall out), and pinch with your fingers at the top to secure. Place baos into the steamer. Give them plenty of room from each other because they will expand and will stick together if you don't have enough room. After 15-20 minutes in steamer (do not open the steamer while they cook), the bao's will be done. Enjoy!
Source of recipe: I wrote the recipe. For more information, please see my blog here: http://veganmiss.blogspot.com/2010/05/dim-sum-char-siu-bao-mango-custard...